The invention relates generally to monitoring and quantifying sport movement (associated either with the person or with the vehicle used or ridden by the person), including the specific parameters of xe2x80x9cairxe2x80x9d time, power, speed, and drop distance. The invention also has xe2x80x9cgamingxe2x80x9d aspects for connecting users across the Internet. The invention is particularly useful in sporting activities such as skiing, snowboarding, mountain biking, wind-surfing, skate-boarding, roller-blading, kayaking, racing, and running, in which sporting persons expend energy, catch xe2x80x9cairxe2x80x9d, move at varying speeds, and perform jumps.
It is well known that many skiers enjoy high speeds and jumping motions while traveling down the slope. High speeds refer to the greater and greater velocities which skiers attempt in navigating the slope successfully (and sometimes unsuccessfully). The jumping motions, on the other hand, include movements which loft the skier into the air. Generally, the greater the skier""s speed, the higher the skier""s loft into the air.
The interest in high speed skiing is apparent simply by observing the velocity of skiers descending the mountain. The interest in the loft motion is less apparent; although it is known that certain enthusiastic snowboarders regularly exclaim xe2x80x9clet""s catch some airxe2x80x9d and other assorted remarks when referring to the amount and altitude of the lofting motion.
The sensations of speed and jumping are also readily achieved in other sporting activities, such as in mountain biking, skating, roller-blading, wind-surfing, and skate-boarding. Many mountain bikers and roller-bladers, like the aforementioned skiers, also crave greater speeds and xe2x80x9cairxe2x80x9d time.
However, persons in such sporting activities only have a qualitative sense as to speed and loft or xe2x80x9cairxe2x80x9d time. For example, a typical snowboarder might regularly exclaim after a jump that she xe2x80x9ccaughtxe2x80x9d some xe2x80x9cbig sky,xe2x80x9d xe2x80x9cbig airxe2x80x9d or xe2x80x9cphat airxe2x80x9d without ever quantitatively knowing how much time really elapsed in the air.
Speed or velocity also remain unquantified. Generally, a person such as a skier can only assess whether they went xe2x80x9cfastxe2x80x9d, xe2x80x9cslowxe2x80x9d or xe2x80x9caveragexe2x80x9d, based on their perception of motion and speed (which can be grossly different from actual speed such as measured with a speedometer or radar gun).
There are also other factors that sport persons sometimes assess qualitatively. For example, suppose a snowboarder skis a double-diamond ski slope while a friend skis a green, easy slope. When they both reach the bottom, the xe2x80x9cdouble-diamondxe2x80x9d snowboarder will have expended more energy than the other, generally, and will have worked up a sweat; while the xe2x80x9cgreenxe2x80x9d snowboarder will have had a relatively inactive ride down the slope. Currently, they cannot quantitatively compare how rough their journeys were relative to one another.
It is, accordingly, an object of the invention to provide systems and methods for determining xe2x80x9cairxe2x80x9d time associated with sport movements.
It is another object of the invention to provide systems and methods for determining the speed of participants and/or vehicles associated with sport movements.
It is yet another object of the invention to provide improvements to sporting vehicles which are ridden by sporting participants, and which provide a determination of speed, airtime, drop distance and/or power of the vehicle.
Still another object of the invention is to provide systems and methods for determining the amount of xe2x80x9cpowerxe2x80x9d or energy absorbed by a person during sporting activities. One specific object is to provide a gauge of energy spent by a sporting participant as compared to others in the same sport, to provide a quantitative comparison between two or more participants.
Yet another object of the invention is to provide the xe2x80x9cdrop distancexe2x80x9d associated with a jump; and particularly the drop distance which occurs within xe2x80x9cairtimexe2x80x9d.
Still another object of the invention is to provide a gaming system to quantitatively compare airtime, drop distance, power, and/or speed between several participants, regardless of their location.
These and other objects of the invention will become apparent in the description which follows.
As discussed herein, xe2x80x9cairxe2x80x9d or xe2x80x9cloftxe2x80x9d time (or xe2x80x9cairtimexe2x80x9d) refer to the time spent off the ground during a sporting movement. For example, airtime according to the invention can include a snowboarder catching air off of a mogul or a ledge. Typically, airtime is greater than one-half (or one-third) second and less than six seconds. In xe2x80x9cextremexe2x80x9d sporting events, the maximum airtime can increase up to about ten or fifteen seconds.
In most cases, it is useful to specify the lower and upper limits of airtimexe2x80x94e.g., from one second to five secondsxe2x80x94so as to reduce processing requirements and to logic out false airtime data. More particularly, the following description provides several techniques and methods for determining airtime. One technique, for example, monitors the vibration of the user""s vehicle (e.g., a ski or snowboard) moving on the ground; and senses when the vibration is greatly reduced, indicating that the vehicle is off the ground. However, when such a user stands in line for the chair-lift, she might remain motionless for thirty seconds or more. By restricting the upper limit to five seconds, a system of the invention can be made to ignore conditions such as standing in line. Similarly, when a user walks slowly, there are cyclical periods of relatively small vibration (e.g., when the user lifts his foot off the ground). Therefore, a lower limit of one-half second or one second are appropriate; so that any detected xe2x80x9cairtimexe2x80x9d that falls below that lower limit is ignored and not stored.
In another aspect of the invention, the measurement of airtime is used to quantify the efficiency by which a person or sport vehicle remain on the ground. By way of example, speed skiers desire to remain on the ground; and the invention thus provides a system which monitors the person and/or vehicle (e.g., the slalom ski) to detect airtime. This information is fed back to the person (in real time or in connection with a later review of video) so that he or she can improve their posture to reduce unwanted airtime. In such applications, airtime is typically less than about three or four seconds; and the lower limit is essentially zero (that is, providing miniscule airtime data can be appropriate for training purposes).
As used herein, xe2x80x9cpowerxe2x80x9d refers to the amount of energy expended by a person or vehicle during a sporting activity, typically over a period such as one ski run. The following description provides several systems, techniques and methods for determining power. Power need not correspond to actual energy units; but does provide a measure of energy expended by the person or vehicle as compared to other persons and vehicles in the same sporting activity. Power can be used to quantify xe2x80x9cbragging rightsxe2x80x9d between sport enthusiasts: e.g., one user can quantify that he expended more energy, or received more xe2x80x9cpunishmentxe2x80x9d, as compared to a friend. Power can refer to the amount of xe2x80x9cG""sxe2x80x9d absorbed during a given period of activity. Power is typically quantified over a period that is selectable by the user. For example, power can be determined over successive one-second periods, or successive five second periods, or successive one minute periods, or successive five minute periods, or other periods. Power can also be measured over a manually selected period. For example, two snowboarders can initialize the period at the beginning of a run down a ski slope and can stop their period at the end of the run.
xe2x80x9cSpeedxe2x80x9d refers the magnitude of velocity as measured during a sport activity. Speed generally refers to the forward direction of the moving sportsman.
xe2x80x9cDrop distancexe2x80x9d refers to the height above the ground as experienced by a user or vehicle during a sport activity. Drop distance preferably corresponds to a measured airtime period. For example, a snowboarder who takes a jump off of a ledge might drop thirty feet (drop distance) in three seconds (airtime). Drop distance can also specifically refer to maximum height above the ground for a given jump (for example, a user on a flat surface can first launch upwards off a jump and return to the same level but experience a five foot drop distance).
The invention thus provides systems and methods for quantifying airtime, power, speed and/or drop distance to quantify a user""s sport movement within one or more of the following activities: skiing, snowboarding, wind-surfing, skate-boarding, roller-blading, kayaking, white water racing, water skiing, wake-boarding, surfing, racing, running, and mountain biking. The invention can also be used to quantify the performance of vehicles upon which users ride, e.g., a snowboard or ski or mountain bike.
The following U.S. patents provide useful background for the invention and are herein incorporated by reference: U.S. Pat. Nos. 5,343,445; 4,371,945; 4,757,714; 4,089,057; 4,722,222; 5,452,269; 3,978,725; and U.S. Pat. No. 5,295,085.
In one aspect, the invention provides a sensing unit which includes a controller subsystem connected with one or more of the following sensors (each of which is described herein): an airtime sensor, a speed sensor, a power sensor, and a drop distance sensor. The controller subsystem includes a microprocessor or microcontroller and can include preamplifiers and A/D converters to interface with the sensor(s) (alternatively, the sensor contains such circuitry). The controller subsystem can further include logic circuitry and/or software modules to logic out unwanted data from the sensors (e.g., airtimes does not correspond to reasonable loft times). Preferably, the controller subsystem also includes digital memory to store parameters for the sensors and to store data such as power, airtime, speed and drop distance (collectively xe2x80x9cperformance dataxe2x80x9d) for later retrieval. A battery typically is used to power the controller subsystem. The battery can also be used for the sensors, if required. However, one preferred sensor which can function for any of the sensors is the piezoelectric foils such as made from AMP SENSORS(trademark). These foils do not require power and rather generate a voltage in response to input forces such as sound. A display can be integrated with the sensing unit to provide direct feedback to the performance data. In one aspect, a user interface is also integrated with the sensing unit to provide user control of the sensing unit, e.g., to include an ON/OFF switch and buttons to select for acquisition or display of certain performance data.
The sensing unit of one aspect is a stand-alone unit, and thus includes a housing. The housing is rugged to survive rigorous sporting activity. Preferably, the housing provides a universal interface which permits mounting of the unit to a variety of vehicle platforms, e.g., onto a ski, snowboard, mountain bike, windsurfer, roller blades, etc. The universal interface is preferably a conformal surface which conveniently permits mounting of the sensing unit to a plurality of surfaces, e.g., a flat surface such as a snowboard, and a round bar such as on a mountain bike.
Alternatively, the sensing unit can be integrated into objects already associated with the sporting activity. In one aspect, the sensing unit is integrated into the ski boot or other boot. In another aspect, the sensing unit is integrated into the binding for a ski boot or snowboarder boot. In still another aspect, the sensing unit is integrated into a ski, snowboard, mountain bike, windsurfer, windsurfer mast, roller blade boot, skate-board, kayak, or other sport vehicle. Collectively, the sport objects such as the ski boot and the variety of sport vehicles are denoted as xe2x80x9csport implementsxe2x80x9d. Accordingly, when the sensing unit is not xe2x80x9cstand alonexe2x80x9d, the housing which integrates the controller subsystem with one or more sensors and battery can be made from the material of the associated sport implement, in whole or in part, such that the sensing unit becomes integral with the sport implement. The universal interface is therefore not desired in this aspect.
In one preferred aspect, the sensing unit provides for the measurement of power entirely within a watch. Manufacturers such as CASIO(trademark), TIMEX(trademark), SEIKO(trademark), FILA(trademark), and SWATCH(trademark) make sport wrist-watches with certain digital electronics disposed therein. In accord with the invention, power measurement capability is added within such a watch so that xe2x80x9cpowerxe2x80x9d data can be provided to sport enthusiasts in all sports, e.g., volleyball, soccer, football, karate, and similar common sports.
In one preferred aspect, the performance data is transmitted via radiofrequencies (or other data transfer technique, including infrared light or inductively-coupled electronics) from the sensing unit to a data unit which is ergonomically compatible with the user. Accordingly, the sensing unit in this aspect does not require a display as performance data is made available to the user through the data unit. For example, the data unit of one aspect is a watch that the user wears on her wrist. The data unit can alternatively be made into a xe2x80x9cpager-likexe2x80x9d module such as known fully in the art (MOTOROLA(trademark) is one well-known manufacturer that makes pager modules). In either case, the sensing unit and the data unit cooperate to provide a complete system for the user.
The data unit can take other forms, in other aspects. For example, the performance data can be transmitted directly to a radio receiver connected to headphones worn by the user or to a small speaker worn in the user""s ear. The radio receiver is for example similar to the SONY(copyright) WALKMAN(copyright), used by plenty of sports enthusiasts. In accord with this aspect of the invention, the sensing unit transmits performance data directly into the receiver so that the user can listenxe2x80x94in real timexe2x80x94to the results of his sports performance. Specifically, the radio receiver includes a data conversion unit which responds to the receipt of performance data from the sensing unit and which converts the performance data into sound, via the headphones, so that the user listens to the performance data. After a jump, for example, the data conversion unit transmits airtime and drop distance data to the user so that the user hears xe2x80x9c1.8 seconds of air, 5 feet drop distancexe2x80x9d.
The data unit can also be made into the pole of a skier, such that a display at the end of the pole provides performance data to the user.
In still another aspect, the data unit is not required. Rather, performance data is transmitted such as by RF directly from the sensing unit to a base station associated with the sporting area. For example, the base station can be a computer in the lodge of a ski area. The sensing unit of this aspect transmits performance data tagged to a particular user to the base station where performance data from all users is collated, stored, compared and/or printed for various purposes. Preferably, the base station includes processing capability and storage whereby performance data can be assessed and processed. For example, a user at the end of the day can receive a print-out (or computer disk) of his performance data; and the report can include a comparison to other performers within the sporting activity. If the activity is snowboarding, for example, the user can see his performance data as compared to other snowboarders on a particular mountain. Performance data can also be catalogued according to age, date, and performance data type (e.g., airtime, power, speed and/or drop distance).
In one aspect, the base station augments the sensing units by providing processing power to calculate and quantify the performance data. For example, in this aspect, raw sensor data such as from a microphone is transmitted from the sensing unit to the base station, which thereafter calculates the appropriate performance data. The sensing unit xe2x80x9ctagsxe2x80x9d the transmitted data so as to identify a particular user. The base station of this aspect then calculates and stores the appropriate performance data for that particular user.
The base station can further include a Web Site server that connects the base station to other such base stations via the Internet so that performance data from users can be collated, stored, compared and/or printed for a variety of purposes. One or more servers thus function as the primary servers from which users can obtain their performance data from their own computers, via the Internet (or via a LAN or WAN). In one aspect, the primary servers also function as a gaming network where performance data from all users is integrated in a recreational manner, and made available to all or selected users.
In one aspect, sensing units (or sensing units and data units) are rented by the owners of a particular sporting area (e.g., a ski area) such as in connection with the rental of a snowboard, or even as a stand-alone device that mounts to the user""s board. The sensing unit can provide real-time performance data to the user, via a connected display or via a data unit. Alternatively, the sensing unit transmits data to the rental facility (or to the base station connected via a LAN to the rental facility) so that the user retrieves his or her performance data at the end of the day.
In one aspect of the invention, performance data is sensed through one or more sensors connected with the sensing unit. It is not desirable to provide all performance data for all sporting activities. For example, for white water rafting or kayaking, a xe2x80x9cpower sensing unitxe2x80x9d is usefulxe2x80x94to quantify the roughness of the ridexe2x80x94but airtime data is practically useless since typically such vehicles do not catch air. In addition, for any given system (i.e., sensing units or sensing units and data units combined), more sensors add cost and require added processing capability, requiring more power draw and reducing battery lifetime. Therefore, certain aspects of the invention provide sensing units that provide only that portion of the performance data that is useful and/or desirable for a given sporting function, such as the following sensing units:
Airtime Sensing Unit
One sensing unit of the invention measures xe2x80x9cairxe2x80x9d time, i.e. the time a person such as a snowboarder or skier is off the ground during a jump. This airtime sensing unit is preferably battery-powered and includes a microprocessor (or microcontoller). The airtime sensing unit either connects to a data unit; or can include a low-powered liquid crystal display (LCD) to communicate the xe2x80x9cairxe2x80x9d time to the user. The components for this airtime sensing unit can include one or more microphones or accelerometers to detect vibration (i.e., caused by friction and scraping along the ground) of the user""s vehicle along the ground, so that xe2x80x9cairtimexe2x80x9d is measured when an appropriate absence of vibration is detected. Preferably, the electronics for the airtime sensing unit are conveniently packaged within a single integrated circuit such as an ASIC. A digital memory stores airtime data; or alternatively, the airtime sensing unit transmits airtime performance data to a data unit or to a base station.
The airtime sensing unit preferably provides several facets of airtime performance data, such as any of the following information data and features:
(1) Total and peak air time for the day. In this aspect, the airtime sensing unit provides at least the peak airtime for the day. The sensing unit can also integrate all airtimes for the day to provide a total airtime.
(2) Total dead time for the day. In this aspect, the airtime sensing unit includes an internal clock that also integrates the time for which no sporting activity is made such as over a given day. For example, dead time can include that time within which the user is at the bar, rather than skiing.
(3) Air time for any particular jump. As discussed above, briefly, this aspect of the airtime sensing unit provides substantially real-time data to the user such as the amount of airtime for a recent jump. By way of example, a data unit with headphones, in one aspect, provide this data to the user immediately after the jump. Alternatively, the airtime data for the jump is stored within memory (either within the data unit or in the sensing unit) so that the user can retrieve the data at his convenience. For example, data for a particular jump can be retrieved from a watch data unit on the chairlift after a particular run which included at least one jump. In this manner, the user can have substantially real-time feedback for the airtime event.
(4) Successive jump records of air time. In this aspect, jump records over a selected period (e.g., one day) are stored in memory either in the data unit or in the airtime sensing unit. These airtime xe2x80x9crecordsxe2x80x9d are retrieved from the memory at the user""s convenience. The system can also store such records until the memory is full, at which time the oldest record is over-written to provide room for newer airtime data. The data can also be transmitted to a base station which includes its own memory storage for retrieval by the user.
(5) Averages and totals, selectable by the user. In this aspect, the sensing unit or data unit (or the base station) saves airtime data within memory for later retrieval by the user. The period for which the data is valid is preferably selectable by the user. The data of this aspect includes airtime averages, over that period, or airtime totals, corresponding to the summation of those airtimes over that period.
(6) Rankings of records. In this aspect, the sensing unit or data unit (or base station) saves airtime data within memory for later retrieval by the user. For example, the user obtains airtime data through the data unit while on the chairlift or later obtains the data in print-out form at the base station, or a combination of the two. The period for which the data is valid is preferably selectable by the user. The data of this aspect includes airtime records, over that period, and the airtime records are preferably ranked by airtime size, the biggest xe2x80x9cairxe2x80x9d to the smallest.
(7) Logic to reject activities which represents false xe2x80x9cairxe2x80x9d time. As discussed above, the preferred airtime sensing unit includes logic circuitry to reject false data, such as standing in line. Typically, the logic sets outer time limits on acceptable data, such as one half second to five seconds for snowboarding, one quarter second to three seconds for roller-blading, and user selected limits, targeted to a particular user""s interest or activity. The logic circuitry of the airtime sensing unit preferably also works with a speed sensor, as discussed herein; and the logic operates to measure airtime only when the sensing unit is moving above a minimum speed. For example, when the sensing unit includes an airtime sensor and a speed sensor, the logic ensures that airtime data is measured only if there is motion. Such logic then ensures that false data corresponding to standing in line is not recorded as performance data. The speed limits tied to the logic are preferably selectable by the user; though certain default speeds are set for certain activities. For example, for skiing and snowboarding, 5 mph is a reasonable lower speed limit, such that all airtime, drop distance and/or power measurements are ignored at lower speeds. For roller-blading, the lower limit of speed is reasonably 1mph, as for wind-surfing.
(8) Toggle to other device functionality. Although this section describes an airtime sensing unit, many sensing units of the invention incorporate at least two sensors, such as: airtime sensor and speed sensor: airtime sensor and power sensor; airtime sensor and drop distance sensor; a combination of airtime, power, and drop distance sensors; a combination of airtime, drop distance and speed sensors; a combination of airtime, power and speed sensors; and a full sensing unit of airtime, speed, power and drop distance sensors. Accordingly, a toggle button is usually included with the sensing unit (or alternatively with the data unit) such that the user can toggle to data corresponding to the desired performance data. Similar toggle buttons can be included with the sensing unit or data unit (which transmits data to the sensing unit) to activate only certain portions of the sensing unit, e.g., to turn off speed sensing. Alternatively, data from any given sensor can be acquired according to user-specified requirements.
Those skilled in the art should appreciate that a sensing unit with multiple sensors can simply acquire all the data, and that the data is sorted according to user needs and requests by toggle functionality at the data unit or at the base station (i.e., such as entering a request for the desired information at the computer keyboard).
(9) User interface to control parameters. As discussed above, the sensing unit and/or data unit preferably include buttons or toggle switches for the user to interact with the unit. For example, one of the units should include an ON/OFF switch, and at least one button to command the display of performance data.
In other aspects, the airtime data of above paragraphs (1)-(6) can be shown on a display connected with the sensing unit, or they can be transmitted to an associated data unit, or to a base station.
Speed Sensing Unit
One sensing unit of the invention measures xe2x80x9cspeed.xe2x80x9d This speed sensing unit is preferably battery-powered and includes a microprocessor (or microcontoller). The speed sensing unit either connects to a data unit; or can include a low-powered liquid crystal display (LCD) to communicate the xe2x80x9cspeedxe2x80x9d to the user. Certain sporting activities also benefit by the measurement of speed, including skiing, snowboarding, mountain biking, wind-surfing, roller-blading, and others. To detect user motion, the sensing unit includes a speed sensor such as a Doppler module, as described in U.S. Pat. Nos. 5,636,146, 4,722,222, and 4,757,714, incorporated herein by reference. Alternatively, the speed sensor can include a microphone subsystem that detects and bins (as a function of frequency) certain sound spectra; and this data is correlated to known speed frequency data. A speed sensor can also include a microphone which, when coupled with the controller subsystem, detects a xe2x80x9cpitchxe2x80x9d of the vehicle; and that pitch is used to determine speed to a defined accuracy (typically at least 5 mph). The speed sensor can alternatively include a Faraday effect sensor (which interacts a magnetic field with an electric field to create a voltage proportional to speed). Specifically, the Faraday effect sensor sets up a current that runs orthogonal to the speed direction. In one aspect, the current is created between two electrodes formed by the two metal edges of a ski or snowboard (in circuit with the snow). When the Faraday effect sensor moves, a voltage is created proportional to velocity. The magnetic field is formed by a magnet that creates a flux substantially perpendicular to the current flow (those skilled in the art should appreciate that the orthogonality of the respective quantities can be compensated by a sine function if the quantities are not orthogonal, to retrieve the speed data).
In another aspect, a sensing unit with a microphone, for example, can benefit by using an electrical filter with a variable bandpass that tracks the dominant spectral content, denoted herein as a xe2x80x9ctracking filter.xe2x80x9d
This speed sensing unit can be stand-alone, or a speed sensor can be integrated into a sensing unit with multiple sensors, such as described above. For example, one speed sensing unit provides both xe2x80x9cairxe2x80x9d time and speed to the user of the device.
Preferably, the electronics for the speed sensing unit are conveniently packaged within a single integrated circuit such as an ASIC. A digital memory stores speed data; or alternatively, the speed sensing unit transmits speed performance data to a data unit or to the base station.
The speed sensing unit preferably provides several facets of speed performance data, such as any of the following information data and features:
(1) Average and peak speed for the day. In this aspect, the speed sensing unit provides at least the peak speed for the day. The sensing unit can also integrate all speeds for the day to provide an average speed.
(2) Speed for any particular period or run. This aspect of the speed sensing unit provides substantially real-time data to the user such as the speed reached in a recent run. By way of example, a data unit with headphones can provide this data immediately (e.g., continually informing the user of data such as xe2x80x9c25 mphxe2x80x9d or xe2x80x9c15 mphxe2x80x9d). Alternatively, the speed data for the run or period is stored within memory (either within the data unit or in the sensing unit) so that the user can retrieve the data at his convenience. For example, data for a particular run or period can be retrieved from a watch data unit on the chairlift after a particular run. In this manner, the user can have substantially real-time feedback for recent periods.
(3) Successive records of speed. In this aspect, peak or average speed records over a selected period (e.g., one day) are stored in memory either in the data unit or in the speed sensing unit. These speed xe2x80x9crecordsxe2x80x9d are retrieved from the memory at the user""s convenience. The system can also store such records until the memory is full, at which time the oldest record is over-written to provide room for newer speed data. The data can also be transmitted to a base station which includes its own memory storage for retrieval by the user.
(4) Averages and totals, selectable by the user. In this aspect, the sensing unit or data unit (or the base station) saves speed data within memory for later retrieval by the user. The period for which the data is valid is preferably selectable by the user. The data of this aspect preferably includes speed averages over that period.
(5) Rankings of records. In this aspect, the sensing unit or data unit (or base station) saves speed data within memory for later retrieval by the user. For example, the user obtains speed data through the data unit while on the chairlift or later obtains the data in print-out form at the base station, or a combination of the two. The period for which the data is valid is preferably selectable by the user. One record can include peak and/or average speed, over that period. The records are preferably ranked by velocity, the fastest to the slowest speeds.
(6) Logic to reject data representing contaminated speed data. The preferred speed sensing unit includes logic circuitry to reject false data, such as data corresponding to two hundred miles per hour. Typically, therefore, the logic sets outer speed limits on acceptable data, such as seventy miles per hour for a skier, as an upper limit, to one or five miles per hour as a lower limit (data that is slower than this rate is not, generally, of interest to skiers). Other reasonable limits are 70 mph to 5 mph for snowboarding, and 40 mph to 5 mph for roller-blading. User selected limits can also be used within the speed sensing unit and targeted to a particular user""s interest or activity.
(7) Toggle to other device functionality. Although this section describes a speed sensing unit, many sensing units of the invention incorporate at least two sensors, such as: speed sensor and power sensor; speed sensor and drop distance sensor; and a combination of speed, power, and drop distance sensors. Accordingly, a toggle button is usually included with the speed sensing unit (or alternatively with the data unit) such that the user can toggle to data corresponding to the desired performance data. Similar toggle buttons can be included with the sensing unit or data unit (which transmits data to the sensing unit) to activate only certain portions of the sensing unit, e.g., to turn off airtime or drop distance sensing. Alternatively, data from any given sensor can be acquired according to user-specified requirements.
(8) User interface to control parameters. As discussed above, the speed sensing unit and/or data unit preferably include buttons or toggle switches for the user to interact with the unit. For example, one of the units should include an ON/OFF switch, and at least one button to command the display of performance data.
In one aspect, a sensing unit with multiple sensors simply acquires all the data, and that data is sorted according to user needs and requests by toggle functionality at the data unit or at the base station (i.e., such as entering a request for the desired information at the computer keyboard).
Power Sensing Unit
One sensing unit of the invention measures xe2x80x9cpowerxe2x80x9d, a measure of the amount of energy absorbed or experienced by a user during a period such as a day. The power sensing unit thus provides a measure of the intensity or how xe2x80x9chardxe2x80x9d the user played during a particular activity. The components for this power distance sensing unit can include one or more microphones or accelerometers to sense vibration or xe2x80x9cjerkxe2x80x9d of the user or the user""s vehicle relative to the ground. For example, one power sensing""unit provides a kayaker with the ability to assess and quantify the power or forces experienced during a white-water ride. The power sensing unit is preferably battery-powered and includes a microprocessor (or microcontoller). In one aspect, xe2x80x9cpowerxe2x80x9d is measured through an accelerometer. In another aspect, the power sensor includes a microphone, as discussed below. As before, the power sensing unit is stand-alone, or it can be incorporated with other units discussed herein. Preferably, the electronics for the power sensing unit are conveniently packaged within a single integrated circuit such as an ASIC. A digital memory stores power data; or alternatively, the power sensing unit transmits power performance data to a data unit. One power sensor according to the invention is an accelerometer, oriented in the direction most indicative of expended energy (e.g., for skiing, the accelerometer is preferably oriented perpendicular to the ski surface). Another power sensor is a microphone, preferably mounted within an enclosure which generates sound in response to user activity.
The power sensing unit preferably provides several facets of power performance data, such as any of the following information data and features:
(1) Peak and average power for the day. In one aspect, a power sensor is an accelerometer which generates analog data that is digitally sampled by the controller subsystem at a rate such as 1000 Hz, 100 Hz or 10 Hz. This digitally sampled data is integrated over a xe2x80x9cpower periodxe2x80x9d such as one-half second, one second, five seconds, ten seconds, fifteen seconds, twenty seconds, thirty seconds, one minute, or five minutes (depending on the sporting activity)xe2x80x94to specify a power xe2x80x9cvaluexe2x80x9d. In another aspect, a peak power is determined for power values over a given user-selected period, e.g., one minute, one day, or other user-selected period, and stored within memory (in the sensing unit, in the data unit, and/or in the base station) for subsequent retrieval by the user. The power sensing unit can also provide an average power value over that period. By way of example, for snowboarding, a user might experience very high power activity over a period of fifteen seconds, such as within a mogul run. By determining power values over one second intervals (i.e., the xe2x80x9cpower periodxe2x80x9d), the mogul run power activity will clearly stand out as a power event in subsequent data analysis. The power period can be user selected, such as over a run down a slope on a mountain. For example, snowboarders over a run down a slope can integrate power values over that period to determine a total value, which can be compared amongst users. Alternatively, the integrated value can be divided by the total number of samples to determine an average power over that run.
(2) Successive power records. In this aspect, peak power records are stored in memory either in the data unit or in the power sensing unit. These power xe2x80x9crecordsxe2x80x9d are retrieved from the memory at the user""s convenience. The system can also store such records until the memory is full, at which time the oldest record is over-written to provide room for newer power data. The data can also be transmitted to a base station which includes its own memory storage for retrieval by the user.
(3) Rankings of records. In this aspect, the power sensing unit or data unit (or base station) saves power data within memory for later retrieval by the user. For example, the user obtains power data through the data unit while on the chair-lift or later obtains the data in print-out form at the base station, or a combination of the two. The period for which the data is valid is preferably selectable by the user. The data of this aspect includes power records, over that period, and the power records are preferably ranked by the largest to the smallest.
(4) Logic to ignore data that contaminates power data. By way of example, data from sensors such as accelerometers can provide noise spikes that correspond to unreasonable power values; and the logic operates to delete such noise spikes.
(5) Toggle to other device functionality. Although this section describes a power sensing unit, many sensing units of the invention incorporate at least two sensors, such as a power sensor and drop distance sensor. Accordingly, a toggle button is usually included with the sensing unit (or alternatively with the data unit) such that the user can toggle to data corresponding to the desired performance data. Similar toggle buttons can be included with the sensing unit or data unit (which transmits data to the sensing unit) to activate only certain portions of the sensing unit, e.g., to turn off drop distance sensing. Alternatively, data from any given sensor can be acquired according to user-specified requirements.
(6) User interface to control parameters. As discussed above, the sensing unit and/or data unit preferably include buttons or toggle switches for the user to interact with the unit. For example, a sensing unit of one aspect includes an-ON/OFF switch and at least one button to command the display of performance data. Since power can be scaled to correspond to real data, such as xe2x80x9cg""sxe2x80x9d or xe2x80x9cjoulesxe2x80x9d, one button can be used to change the units of the power values.
Drop Distance Sensing Unit
One sensing unit of the invention measures xe2x80x9cdrop distancexe2x80x9d. This drop distance sensing unit is preferably battery-powered and includes a microprocessor (or microcontoller). The drop distance sensing unit either connects to a data unit; or can include a low-powered liquid crystal display (LCD) to communicate the xe2x80x9cdrop distancexe2x80x9d to the user. The components for a drop distance sensing unit of one aspect includes a pressure sensor or altimeter. Preferably, the electronics for the drop distance sensing unit are conveniently packaged within a single integrated circuit such as an ASIC. A digital memory unit stores drop distance data; or alternatively, the drop distance sensing unit transmits drop distance performance data to a data unit.
The drop distance sensing unit preferably provides several facets of drop distance performance data, such as any of the following information data and features:
(1) Total and peak drop distance for the day. In this aspect, the drop distance sensing unit provides at least the peak drop distance for the day. The sensing unit can also integrate all drop distances for the day to provide a total drop distance.
(2) Drop distance for any particular jump. This aspect of the drop distance sensing unit provides substantially real-time data to the user such as the drop distance for a recent jump. By way of example, in one aspect, a data unit with headphones provides this data immediately after the jump. Alternatively, the drop distance data for the jump is stored within memory (either within the data unit or in the sensing unit) so that the user can retrieve the data at his convenience. For example, data for a particular jump can be retrieved from a watch data unit on the chairlift after a particular run which included at least one jump. In this manner, the user can have substantially real-time feedback for the drop distance event.
(3) Successive jump records of drop distance. In this aspect, jump records over a selected period (e.g., one day) are stored in memory either in the data unit or in the drop distance sensing unit (or at the base station). These drop distance xe2x80x9crecordsxe2x80x9d are retrieved from the memory at the user""s convenience. The system can also store such records until the memory is full, at which time the oldest record is over-written to provide room for newer drop distance data. The data can also be transmitted to a base station which includes its own memory storage for retrieval by the user.
(4) Averages and totals, selectable by the user. In this aspect, the sensing unit or data unit (or the base station) saves drop distance data within memory for later retrieval by the user. The period for which the data is valid is preferably selectable by the user. The data of this aspect includes drop distance averages, over that period, or drop distance time totals, corresponding to the summation of those drop distances over that period.
(5) Rankings of records. In this aspect, the sensing unit or data unit (or base station) saves drop distance data within memory for later retrieval by the user. For example, the user obtains drop distance data through the data unit while on the chair-lift or later obtains the data in print-out form at the base station, or a combination of the two. The period for which the data is valid is preferably selectable by the user. The data of this aspect includes drop distance records, over that period, and the drop distance records are preferably ranked by size, the largest distance to the smallest.
(6) Logic to reject activities which represents false drop distance. The preferred drop distance sensing unit includes logic circuitry to reject false data. Typically, the logic sets outer drop distance limits on acceptable data, such as three feet to one hundred feet for snowboarding and skiing (or up to 150 feet for extreme sports), and user selected limits, targeted to a particular user""s interest. The logic circuitry of the drop distance sensing unit preferably also works with an airtime sensor, as discussed above; and the logic operates to measure drop distance only when there is a detected airtime. For example, when the sensing unit includes an airtime sensor and a drop distance sensor, the logic ensures that drop distance data is measured only if there is an airtime event, which can include its own logic as discussed above. The limits for other sports varies. In roller-blading, for example, the drop distance limits can be set to one foot minimum to ten or fifteen feet maximum.
(7) Toggle to other device functionality. Although this section describes a drop distance sensing unit, many sensing units of the invention incorporate at least two sensors, such as: drop distance sensor and speed sensor; drop distance sensor and power sensor; drop distance sensor and airtime sensor; and combinations. Accordingly, a toggle button is usually included with the sensing unit (or alternatively with the data unit) such that the user can toggle to data corresponding to the desired performance data. Similar toggle buttons can be included with the sensing unit or data unit (which transmits data to the sensing unit) to activate only certain portions of the sensing unit, e.g., to turn off speed sensing. Alternatively, data from any given sensor can be acquired according to user-specified requirements.
(8) User interface to control parameters. As discussed above, the sensing unit and/or data unit preferably include buttons or toggle switches for the user to interact with the unit. For example, the sensing unit of one aspect includes an ON/OFF switch, and at least one button to command the display of performance data such as drop distance.
In one aspect, the invention incorporates a pair of power meters that measure and quantify a competitor""s performance during mogul competitions. In this application, one device is mounted to the ski (or lower body, such as the lower leg), and another to the upper body. An RF signal unit communicates readings from both devices to a signal controller at the judge""s table. The combined signals determine the force differential between the lower legs and the upper body, giving an actual assessment of a competitor""s performance. The device starts transmitting data at the starting gate. The device of this aspect can also be coupled to the user via a data unit with headphones to provide a hum or pitch which tells the user how effective his/her approach is.
In another aspect, the invention provides a performance system which gauges the negative airtime aspects of speed skiers. For example, it is undesirable for skiers such as Tommy Moe to lift off of the ground during training, and certainly during a speed event, which slows the skier""s speed. In this aspect, the system informs the user (in real time, via a data unit) of instances of air time so that the skier can adjust and improve his competitive position. Airtime in this aspect is thus typically less than three seconds and can be as small as one tenth of a second or less. The data is preferably also communicated to a base station so that the data can be replayed together with a video of the run, so that the skier can get feedback of airtime (unwanted in speed skiing) while watching his technique.
In another aspect, the invention provides a speed and airtime sensing unit such as described above, and additionally provides a height sensor integrated with the sensing unit. In one aspectxe2x80x94identified herein as the xe2x80x9cdefaultxe2x80x9d height measurexe2x80x94the height sensor detects speed and converts that speed data to height. Many jumps performed in sporting events such as snowboarding occur off of a ledge, such that xe2x80x9cheightxe2x80x9d is determined solely by the force of gravity. In one aspect, therefore, drop distance height is determined by xc2xd at2, where a is the acceleration due to gravity (9.81 meters per second squared, at sea level) and where t is airtime, as determined by an airtime sensor as described herein. By way of example, for a one second airtime, a drop distance of 4.9 meters is measured. This result is approximately true even if the airtime occurs on a slope down a mountain. However, this calculation will be in error if there is an upward or downward motion at the start of the airtime. For example, if a jump occurs off of a mogul and the user is launching upwards into the air, then this calculation will produce an incorrect number. Accordingly, the height sensor preferably includes a level sensor which senses and measures the angle of motion relative to a plane perpendicular to the force of gravity. This angle determines the distance which should be added or subtracted from the default measure. By way of example, if at the beginning of a two second airtime the user moves at a speed of 10 mph (about 4.47 m/s), at an angle of 15 degrees upwards (such as off a mogul), then the velocity vector in the vertical direction, Vv, is sin(15xc2x0)*10 mph; and the distance added to the default measure is approximately sin(15xc2x0)*2(Vv2)/a, or 1.05 m. The time for this upward-traveled distance is sin(15xc2x0)*2Vv/a, or 0.24s. The default time in this example is thus total airtimexe2x80x940.24s; and the default measure is 15.2 m. The total drop distance is then 15.2 m plus 1.05 m, or 16.25 m.
In one aspect, the invention provides a system for determining the loft time of a moving vehicle off of a surface. A loft sensor senses a first condition that is indicative of the vehicle leaving the surface, and further senses a second condition indicative of the vehicle returning to the surface. A controller subsystem, e.g., typically including a microprocessor or microcontroller, determines a loft time that is based upon the first and second conditions, and the loft time is preferably displayed to a user of the system by a display, e.g., a LCD or LED display. In another aspect, a power module such as a battery is included in the system to power the several components. In addition, a housing preferably connects and protects the controller subsystem and the user interface; and further includes an interface (possibly including velcro) that facilitates attaching the housing to the vehicle.
One preferred aspect of the invention includes a speed sensor, connected to the controller subsystem, which senses a third condition that is indicative of a velocity of the vehicle (or at least indicates that the vehicle is in forward motion). In this aspect, the controller subsystem includes means for converting the third condition to information representative of a speed of the vehicle. Alternatively, the speed sensor is used as logic for the airtime sensor to switch off the collection of data when there is no forward motion. According to one aspect, the system provides a user with airtime and speed of the vehicle.
In yet another aspect, a display of the invention displays selective information, including one or more of the following: the loft time; a speed of the vehicle; a peak loft time; an average loft time; a total loft time; a dead time; a real activity time; an average speed; successive records of loft information; successive records of speed information; a distance traveled by the vehicle; and a height achieved by the vehicle off of the surface.
In still another aspect, the invention includes a user interface for providing external inputs to the sensing and/or data units, including one or more of the following: a start/stop button for selectively starting and stopping the acquisition of data; a display-operate button for activating the display selectively; a speed/loft/power/drop distance toggle button for alternatively commanding a display of different performance data; means for commanding a display of successive records of performance data selectively; means for commanding a display of information corresponding to average performance data; means for commanding a display of dead time; means for commanding a display of distance traveled by the vehicle upon which the user rides; means for commanding a display of height achieved by the vehicle off of the surface; and means for commanding a display of real activity time.
Preferably, the controller subsystem of the invention includes a clock element, e.g., a 24-hour clock, for providing information convertible to an elapsed time. Accordingly, the subsystem can perform various calculations, e.g., dead time, on the data acquired for display to a user. The clock can also be incorporated into a data unit, as a matter of design choice.
In another aspect, the airtime sensor is constructed with one of the following technologies: (i) an accelerometer that senses a vibrational spectrum; (ii) a microphone that senses a noise spectrum; (iii) a switch that is responsive to a weight of a user of the vehicle; (iv) a voltage-resistance sensor that generates a voltage indicative of a speed of the vehicle; and (v) a plurality of accelerometers connected for evaluating a speed of the vehicle.
In another aspect, induced-strain sensors, such as a piezoceramics (e.g., PZT, or lead zirconate), piezopolymer (e.g., PVDF), or shape memory (e.g., NiTiNOL) elements can be used in sensors discussed herein. An xe2x80x9cinduced strainxe2x80x9d sensor provides a measurable output such as a voltage in response to an applied strain, generally a compressive strain. Also, strain gages and load cells (which are usually made using strain gage bridges) can also be incorporated into sensors herein: the former for measuring bending strains, the latter for forces and compressive strains. In still another aspect, FSRs (force sensing resistors), such as those manufactured by IEE Interlink, can be used. The FSRs are pads consisting of inter-digitated electrodes over a semi-conductive polymer ink, wherein the resistance between the electrodes decreases nonlinearly as a function of applied compressive load, with high sensitivity and low cost.
In a preferred aspect, the airtime sensor of the invention senses a spectrum of information, e.g., a vibrational or sound spectrum, and the controller subsystem determines the first and second conditions relative to a change in the spectrum of information. Further, the controller subsystem interprets the change in the spectrum to determine the loft time.
For example, one aspect of an airtime sensor according to the invention includes one or more accelerometers that generate a vibrational spectrum of the vehicle. In such an aspect, the first and second conditions correspond to a change in the vibrational spectrum. By way of another example, one airtime sensor of the invention includes a microphone subassembly that generates voltages corresponding to a noise spectrum of the vehicle; and, in this aspect, the first and second conditions correspond to a change in the detected noise spectrum. Because these spectrums are influenced by the particular activity of a user, e.g., standing in a ski line, a controller subsystem of the invention preferably includes logic for assessing boundary conditions of the spectrum and for excluding certain conditions from the determination of airtime. Accordingly, if a skier is in a lift line, such conditions are effectively ignored. One boundary condition, therefore, according to an aspect of the invention, includes an elapsed time between the first condition and the second condition that is less than approximately 500 ms; such that events that are within this boundary condition are excluded from the determination of airtime. One other boundary condition, in another aspect, includes an elapsed time between the first condition and the second condition that is greater than approximately five seconds; such that events that are outside this boundary condition are excluded from the determination of airtime. Because these boundary conditions are important in the aspects of the invention which utilize a spectrum of information, the sensing and/or data units preferably utilize a user interface to provide selective external inputs to the controller subsystem and for adjusting the boundary conditions selectively.
In one aspect, the change in a vibration or sound spectrum is detected through waveform xe2x80x9cenvelopingxe2x80x9d of the time domain signal, and then by passing the output of this envelop to a threshold-measuring circuit. Pre-filtering of the signal, especially to remove low-frequency content beyond high pass filtering, can also be included.
In still another aspect, the controller subsystem determines a pitch of the spectrum by isolating a best-fit sine wave to a primary frequency of at least part of the spectrum and by correlating the pitch to a vehicle speed. Accordingly, the invention of this aspect detects spectrum information and correlates that information to a speed of the vehicle. Typically, a higher pitch frequency corresponds to a higher vehicle speed and a lower pitch frequency corresponds to a lower vehicle speed. However, in another aspect, the selected pitch frequency is calibrated relative to a selected vehicle and speed.
In still another aspect, speed is inferred by the amount of energy at different vibrational frequencies, as discussed herein.
The invention also provides, in another aspect, means for storing information including look-up tables with pitch-to-speed conversions for a plurality of vehicles. This is useful because different vehicles have different associated noise and/or sound spectrums associated with the vehicle. Accordingly, the invention in this aspect includes memory for storing the respective calibration information of the different vehicles (typically in a look-up table format) so that a user can utilize the invention on different vehicles and still accurately determine speed. Specifically, a particular pitch is associated with a particular speed for a particular vehicle; and that association is selectively made by the user.
In several aspects of the invention, the controller subsystem includes one or more of the following: means for selectively starting and stopping the acquisition of data by the sensing unit; means for responding to an external request to activate a display for the display of performance data; means for responding to an external request to alternatively display airtime, drop distance, speed and/or power; and/or means for responding to an external request to display successive records of performance data.
The invention also provides certain methodologies. For example, in one aspect, the invention provides a method for determining the loft time of a moving vehicle off of a surface, comprising the steps of: (1) sensing the vehicle leaving the surface at a first time; (2) sensing the vehicle returning to the surface at a second time; and (3) determining a loft time from the first and second times. Preferably, the loft time is provided to the user who performed the jump via one of the following methods: through a display located with the user, either in a data unit or within a sensing unit; through a real time feedback heads-up display or headphones; through a report available at a base station located at the area where the jump occurred, such as after a day of skiing; and/or through a computer linked to a network like the Internet, where the airtime data is stored on a server on the network, such as a server located at the area where the jump occurred.
In still another aspect, the invention provides a method of measuring the amount of xe2x80x9cpowerxe2x80x9d a user absorbs during the day. A motion sensor, e.g., a microphone or accelerometer, attaches to the vehicle, preferably pointing perpendicular to the top of the vehicle (e.g., perpendicular to the top surface of the snowboard) so that a measure of acceleration, xe2x80x9cforcexe2x80x9d, jerk or jar associated with the user is made. The data from the motion sensor is integrated over a selected timexe2x80x94e.g., over the time of the skiing day, or over power periods such as one minute intervalsxe2x80x94so that an integrated measure of motion is acquired. By way of example, if the motion sensor is an accelerometer positioned with a sensitive axis arranged perpendicular to the top snowboard surface, then, through integration over the power period, an integrated measure of xe2x80x9cpowerxe2x80x9d is obtained.
Those skilled in the art should appreciate that power can be converted to actual power or similar unitsxe2x80x94e.g., watts or joules or ergs or Newtonsxe2x80x94though real units are not as important as having a constant, calibrated measure of xe2x80x9cpowerxe2x80x9d for each user. That is, suppose two snowboarders have power sensors on their respective snowboards. If one person skis a green slope and another skis a double-diamond, then the integrated value out of the double-diamond snowboarder will be greater. The units are therefore set to a reasonably useful value, e.g., generic power xe2x80x9cUNITSxe2x80x9d. In one aspect, the power units are set such that a value of xe2x80x9c100xe2x80x9d indicates a typical snowboarder who skies eight hours per day and on maximum difficult terrain. At the same time, a snowboarder who rides nothing but green beginner slopes, all day, achieves something far less, e.g., a value of xe2x80x9c1xe2x80x9d. In this manner, average skiers on blue, intermediate slops will achieve intermediate values, e.g., xe2x80x9c20xe2x80x9d to xe2x80x9c50xe2x80x9d. Other scales and units are of course within the scope of the invention, and should be set to the particular activity.
Units for airtime are preferably set to seconds, such as xe2x80x9c1.2sxe2x80x9d. Units for speed are preferably set to miles per hour, killometers per hour, meters per second, feet per second, inches per second, or centimeters per second. Units for drop distance are preferably set to feet, meters, inches, or centimeters.
In one aspect, the sensing unit (and/or the data unit) has a user interface. The interface can include a display and/or audible feedback such as through headphones In one aspect, the audible feedback informs the user of big xe2x80x9cairxe2x80x9d words such as xe2x80x9cawesomexe2x80x9d if for example a snowboarder hit really big air (e.g., over five seconds). In another aspect, the interface electronics include a low-power piezo xe2x80x9cbuzzerxe2x80x9d or headphone xe2x80x9cbudxe2x80x9d speaker that sounds whenever an xe2x80x9cairxe2x80x9d condition is sensed. This provides immediate feedback to the user. Further, in another aspect a varying pitch is used to give a speed indication. For instance, the ear can readily distinguish an octave pitch change, which can for example correspond to each 5 mph change in speed.
The measure of power according to the invention thus provides significant usefulness in comparing how strenuous one user""s activity is as compared to another. For example, suppose two users ski only blue, intermediate slopes with the exact same skill and aggressiveness except that one user chooses to sit in the bar for three hours having a couple of cocktails. At the end of an eight hour dayxe2x80x94providing the power period is set for the whole dayxe2x80x94the skier who skied all eight hours will have a power measurement that is 8/5 that of his cocktail-drinking companion. They can thereafter quantitatively talk about how easy or how difficult their ski day was. As for another example, suppose a third friend skis only double-diamond slopes and he takes four hours out to drink beer. At the end of the day, his power measure may still be greater than his friends depending upon how hard he skied during his active time. He could therefore boastxe2x80x94with quantitative power data to back him upxe2x80x94that he had more exercise than either of his friends even though he was drinking half the day.
In one aspect, the invention incorporates a breathalyzerxe2x80x94used to measure a user""s consumption (i.e., a blood alcohol level)xe2x80x94and the level is stored such as within the memory within the controller subsystem. A base station can upload the data to the memory, as desired.
The measure of air time, according to the invention, can also be used in a negative sense. That is, speed skiers try to maintain contact with the ground as air time decreases their speed. By monitoring their air time with the invention, they are better able to assess their maneuvers through certain terrain so as to better maintain ground contact, thereby increasing their speed.
The measurement of air, speed and power, and drop distance, in accord with the invention, are preferably made through one or more sensors located with the vehicle, e.g., on the snowboard or ski, upon which the person rides. As such, it is difficult to see the sensor; so one aspect the invention provides an RF transmitter in the sensing unit. A data unit coupled to the RF transmitterxe2x80x94e.g., in the form of a watch, paging unit, or radio receiver with headphones, is located at a convenient location with the person. The performance dataxe2x80x94e.g., air, power, drop distance and speedxe2x80x94is transmitted to the person for convenient viewing, or listening. In still other aspects, a memory element in the data unit (or alternatively in the sensing unit) provides for storing selected parameters such as successive records of speed, air, drop distance and power, or averages for the performance data. Data can also be transmitted from the sensing unit to a base station, as discussed above. Those skilled in the art should appreciate that other data transfer techniques can be used instead of RF, including IR data transfer between the units.
In one aspect, the sensing unit internally resets (i.e., shuts off) when the unit senses no reasonable or useful performance data for a preselected period of time. By way of example, through a clock within the microprocessor, the unit automatic time-outs after that period, saving battery power.
In one aspect, a temperature sensor is included with the sensing unit (or data unit). A temperature profile is taken over the course of a activity day and is later displayed so that the user may boast that he or she skied in the most arduous situations.
Preferably, performance data is accumulated and then transmitted to a base station such as a ski lodge. For mountain biking, data can be telemetered back to a club house. Through the use of Internet connectivity, these data sets can also be downloaded off a Web site so that the user can compare different slopes or areas, together with performance. The data can also be evaluated and figures of merit can be applied to each run so that a skier can look at his or her performance and see how they did relative to other users. A skier may find for example that he skied better on that trail than any one else all month, year or ever. A handicap can also be applied to other mountains and trails so that a national or world competition is achieved. This interconnectivity is permitted by use of the World Wide Web or simply by using bulletin boards that are called up and updated, as known in the art. Telenet or FTP sites can also contact each other or be contacted by a home site that will assimilate the data and prepare it for display. Security could be ensured so that a user has confidence that only he or she can access their own data.
The invention thus provides, in one aspect, a national or regional game to be played so that the many users can compare and store performance data. Ski areas may use this data, for example, with the participant""s knowledge and consent so that it will lure skiers to their lifts in the hope that they will win an award. Awards for the highest vertical drop, most air time, greatest speed or most power may also be awarded. The prizes could simply be free lift tickets.
In one aspect, power for the sensing units (or data units) may be saved during times of inactivity by powering off most of the electronics with a solid state switch such as a MOSFET. The processor or some minimum electronics can remain powered so that when activity is detected, the remaining electronics are powered as needed. Further, to save power, sensors such as accelerometers are duty cycled.
In another aspect, downward velocity is determined by knowing the rate of descent such as through a pressure sensor. Pressure sensing and airtime can thus be used to determine vertical drop, where loft is determined by the absence of a vibratory noise floor, for example.
In another aspect, the GPS is used to determine speed down a slope. With updates as frequent as one second, there is more than enough bandwidth to acquire changing GPS data. GPS however can have large errors associated with uncertainty of positioning calculations. This may be remedied by using differential GPS. Differential GPS makes use of a fixed GPS receiver with a known position, such as at the base station. When functioning as a sensor, therefore, the GPS receiver receives updates from the base station to maintain accurate position. When large errors are received, they are rejected because the fixed receiver is at a known position, resulting in a data correction that is also applied to the moving receiver on the slope. In some areas of the United States, the correction codes for differential GPS are broadcast for general use.
In still another aspect, when using a GPS receiver, individual ski maps for each trail are downloaded into memory so that the skier may see where they are on the display. Also, 3D topographical information is also preferably downloaded so that features can be attached to these maps and to aid in performance data determination. By knowing the height in 3D space of the receiver, and with the stored height of the slope in memory, the distance off the ground is determined. Loft time is also thus determined in addition to vertical drop. Loft detection with a GPS system may thus return the value of drop distance.
In another aspect, speed is determined by use of neural network synthesis. A neural network extracts speed information from a sensor such as a microphone or an accelerometer. This is accomplished, for example, by recording microphone data on a ski or snowboard along with a true speed sensor, such as a Doppler microwave sensor. Two data sets are thus generated: the first data set contains data acquired from the microphone that will be used in the final system; and the second data set corresponds to the true device that is used as a reliable speed detector. These two data sets are fed into a neural network, and the output of the neural filter is then compared with known good speed data. The various weights of the neural network are adjusted until a match is determined. At this point, the neural network is used to process the first data set to reliably determine speed. In the event that a match is not found, a more complex but powerful network is developed. The first data set is then fed into the new net and a match is developed by adjusting the weights of the nodes. This process is repeated constantly until a match is determined. Each failure results in a larger neural network but increases the probability that the next filter will achieve a match.
In areas where the ski run is visible, the speed and trajectory of a skier may be achieved by the use of a digital imaging system, in accord with another aspect. The imaging system can thus include a CCD camera that looks at the slope and watches skiers traverse down the slope. By knowing the distances along the slope, and the fact that the camera is stationary, the distance moved is determined frame to frame, corresponding to position in time that correlates to speed. Skiers can be identified by signs they wear, including a distinctive pattern which allows identification of individual skiers.
The invention is next described further in connection with preferred embodiments, and it will be apparent that various additions, subtractions, and modifications can be made by those skilled in the art without departing from the scope of the invention